The area of this invention is the preparation and use of a frying oil which produces a highly preferred flavor profile in fried foods while providing optimum fry life stability in a beef tallow containing frying oil.
Kuss (U.S. Pat. No. 5,073,398) teaches that desirable flavor compounds in beef tallow are a low boiling volatile fraction which can be transferred from beef tallow to vegetable oil by passing a carrier gas first through the tallow at a temperature of 150xc2x0 F. or greater and then through a vegetable oil. The resulting beef tallow flavored vegetable oil lost the beef tallow flavor after brief period of use, however, demonstrating that the volatile constituents themselves do not provide long lasting flavor enhancement.
Yang (U.S. Pat. No. 5,104,678) teaches that the flavor compounds of beef tallow arise from minor unsaturated fatty acid constituents. To isolate the effect of these fatty acids, Yang isolated the fatty acids, reconstituted the triglyceride and then deodorize the resulting triglyceride. The resulting product is said to develop beef tallow flavors upon heating. It would seem reasonable that these minor fatty acids would exert their flavor development in their natural state. The present inventors have found, however, that well deodorized beef tallow does not develop a preferred flavor profile when heated.
A particular challenge in the formulation of frying oils is that initial oil flavor may quickly degenerate to a highly undesirable flavor. Unlike most other oil uses, a frying oil must maintain its flavor over a period several days under highly adverse conditions of high temperature, exposure to oxygen and introduction of pro-oxidants from the foods being fried. Under these circumstances, it has become common practice in the edible oil industry to measure the oxidative stability of frying oil using such methods as Active Oxygen Method or the Oxidative Stability Index as a surrogate for the flavor stability of the oil. Remarkably the present inventors have learned that maximum flavor stability and intensity in beef tallow containing frying oils can be achieved by reducing the oxidative stability of a frying oil slightly and that such changes can be directed by careful control of the composition of the tallow fraction.